Proteomic analysis of human vessels: application to atherosclerotic plaques

Atherosclerosis is a chronic disease that affects medium and large arteries. This process originates from the interaction between cells of the arterial wall, lipoproteins and inflammatory cells, leading to the development of complex lesions or plaques that protrude into the arterial lumen. Plaque rupture and thrombosis result in acute clinical complications such as myocardial infarction and stroke. Owing to the heterogeneous cellular composition of the plaques, a proteomic analysis of the whole lesion is not appropriate. Therefore, we have studied the proteins secreted by human carotid atherosclerotic plaques, obtained by endarterectomy. Normal artery segments and different regions of the surgical pieces (noncomplicated plaque, complicated plaque with thrombus) were cultured in protein-free medium and the secreted proteins (supernatants) analyzed by two-dimensional gel electrophoresis. Normal artery segments secreted a moderate number of proteins (42 spots). However in the two-dimensional (2-D) gels (pH 3-10) of segments bearing a plaque, the number of spots increased markedly (154). The number of spots also increased (202) in the 2-D gels of artery segments with a ruptured plaque and thrombus. Thus, the more complicated the lesion, the higher the number of secreted proteins, suggesting the production of specific proteins relating to the complexity of the atherosclerotic lesion.     

颈动脉斑块LRNC特征可诊断2型糖尿病患者急性脑梗死的风险

2型糖尿病可能加重颈动脉斑块的易损性并增加缺血性中风的风险,关于2型糖尿病患者伴有颈动脉斑块特征的急性中风亚型鲜有研究报道。本研究旨在探讨2型糖尿病患者颈动脉斑块特征与MRI确定的急性脑梗死病变特征之间的关系。本研究以颈内动脉区急性脑血管病患者为研究对象,所有患者分为2型糖尿病组和非2型糖尿病组,分别行颈动脉和脑部MRI扫描,测定同侧颈动脉斑块的形态和特征,以及颅内和颅外颈动脉狭窄。基于中风亚型和急性脑梗塞病变模式对患者进行评估。研究结果表明,与非2型糖尿病患者相比,2型糖尿病患者颈动脉型IV-VI病变的患病率更高,斑块负荷更大,以及富脂质坏死核(LRNC)更大。在有症状的颈动脉LRNC患者中,与非2型糖尿病组相比,2型糖尿病组颈内动脉区出现较多的伴有大穿孔动脉梗塞形态和较大的急性脑梗塞。LRNC%>23.5%的颈动脉斑块是2型糖尿病患者存在颈动脉狭窄的急性脑梗塞病变的独立危险因素。颈动脉斑块特征的量化,尤其是MRI诊断的富脂质坏死核对中风风险具有潜在应用价值。     

比较两种测量方法获得的血压波动对老年颈动脉斑块的影响

目的:比较两种不同血压波动测定方法测定的血压波动与颈动脉斑块发生的关系。方法:以1456名患有动脉硬化老年男性患者为研究对象,监测患者24 h动态血压,根据有无颈动脉斑块将入选患者分为2组:颈动脉斑块组(n=1012)和无颈动脉斑块组(n=444),分别采用经典的标准差方法(SD法)和个体血压波动测定方法(个体法)分别测定每位患者的血压波动,回顾性分析这两种方法测定的血压波动与颈动脉斑块形成的关联性。结果:SD法测定颈动脉斑块组24 h收缩期血压波动(SBPV)、白天SBPV、夜间SBPV以及24 h舒张期血压波动(DBPV)水平均明显高于无颈动脉斑块组(P0.05);而白天和夜间DBPV差异无统计学意义。个体法测定颈动脉斑块组24 h SBPV、白天SBPV、24 h DBPV以及白天DBPV水平较无颈动脉斑块组均明显升高(P0.05);夜间SBPV和夜间DBPV差异无统计学意义(P0.05)。比较颈动脉斑块组SBPV值出现次数,SD法测定SBPV最多的是10-15 mmHg(n=541),其次是大于15 mmHg(n=399);个体法测定颈动脉斑块组SBPV值出现次数最多的是0-8 mmHg(n=490),其次是8-10 mmHg(n=350)。结论:在老年男性动脉硬化相关疾病患者中,血压波动与颈动脉斑块的形成有着密切的关系,两种方法均可测定血压波动,但以个体血压波动测定方法更加敏感。     

Histochemical evidence for inducible nitric oxide synthase in advanced but non-ruptured human atherosclerotic carotid arteries

In response to cytokine stimulation, the inducible isoform of the nitric oxide synthase (iNOS) produces large amounts of nitric oxide with potential consequences in the pathophysiology of atherosclerosis. Previous investigations have demonstrated the presence of iNOS in human atherosclerotic lesions. The goal of this study was to evaluate the occurrence of the expression of iNOS in ruptured versus non-ruptured human carotid atherosclerotic plaques. Using plastic-embedded sections, we performed in situ hybridization and immunohistochemistry on very advanced atherosclerotic lesions type V (non-ruptured) and type VI (ruptured) from 12 atheromatous carotid arteries from endarterectomy and six non-atherosclerotic internal mammary arteries from aorto-coronary bypass. Only one internal mammary artery expressed iNOS in the endothelium. In contrast, iNOS mRNA and protein were repeatedly expressed in advanced lesions type V in 5/7 cases, particularly in inflammatory regions. Specific cell markers identified iNOS-positive cells as macrophages and T-lymphocytes but also as smooth muscle cells and endothelial cells adjacent to these inflammatory regions. Nitration of protein tyrosines was not always associated to iNOS expression but more likely to the presence of inflammatory cells. In complicated lesions type VI, the occurrence of iNOS mRNA and protein expression diminished drastically (1/5 cases). Combined expression of iNOS mRNA and protein is frequently found in advanced but non-ruptured human atherosclerotic carotid lesions while it becomes rare after the plaque has ruptured. These findings suggest that iNOS could be an active participant in the plaque rupture event.     

MRI对糖尿病急性脑梗死患者颈动脉粥样硬化斑块稳定性的评估价值

目的:探讨核磁共振成像(MRI)对急性脑梗死合并糖尿病患者颈动脉粥样硬化斑块稳定性的评估价值。方法:选取2013年5月-2015年5月在我院接受治疗的83例糖尿病合并急性脑梗死患者作为研究组,另选择单纯急性脑梗死患者61例作为对照组。两组患者均采用MRI评估颈动脉血管及斑块稳定性,并分析影响颈动脉斑块稳定性的危险因素。结果:研究组患者颈动脉粥样硬化易损斑块的发生率高于对照组,差异具有统计学意义(P0.05);研究组患者斑块最大厚度明显高于对照组,差异具有统计学意义(P0.05);两组患者血管总面积、血管壁面积、血管腔面积及血管壁标准化指数比较,差异均无统计学意义(P0.05)。性别、糖尿病以及饮酒是影响急性脑梗死患者颈动脉斑块稳定性的独立危险因素(P0.05)。结论:MRI能够有效评估急性脑梗死患者颈动脉粥样硬化斑块的稳定性,有利于临床诊断以及确定治疗方案,值得推广应用。     

Fractalkine Is Expressed in Early and Advanced Atherosclerotic Lesions and Supports Monocyte Recruitment via CX3CR1

Fractalkine (CX3CL1, FKN) is expressed in the inflamed vascular wall and absence of FKN reduces atherogenesis. Whether FKN is expressed throughout all stages of atherosclerotic disease and whether it directly contributes to monocyte recruitment to atherosclerotic lesions is not known. We collected human atherosclerotic plaque material and blood samples from patients with carotid artery disease undergoing endarterectomy. Plaques were analyzed by immunohistochemistry and qPCR. We found that FKN is expressed at all stages of atherosclerotic lesion formation, and that the number of FKN-expressing cells positively correlates with the number of CX3CR1-positive cells in human carotid artery plaques. In the circulation, soluble FKN levels are significantly elevated in the presence of high-grade (sub-occlusive) stenosis. To determine the role of the FKN-CX3CR1 axis for monocyte adhesion in vivo we then performed intravital videofluorescence microscopy of the carotid artery in ApoE(-/-) mice. Notably, FKN-CX3CR1 interactions are critical for recruitment of circulating monocytes to the injured atherosclerotic vascular wall. Thus, this chemokine dyad could represent an attractive target for anti-atherosclerotic strategies.     

Experimental determination of circumferential properties of fresh carotid artery plaques

Carotid endarterectomy (CEA) is currently accepted as the gold standard for interventional revascularisation of diseased arteries belonging to the carotid bifurcation. Despite the proven efficacy of CEA, great interest has been generated in carotid angioplasty and stenting (CAS) as an alternative to open surgical therapy. CAS is less invasive compared with CEA, and has the potential to successfully treat lesions close to the aortic arch or distal internal carotid artery (ICA). Following promising results from two recent trials (CREST; Carotid revascularisation endarterectomy versus stenting trial, and ICSS; International carotid stenting study) it is envisaged that there will be a greater uptake in carotid stenting, especially amongst the group who do not qualify for open surgical repair, thus creating pressure to develop computational models that describe a multitude of plaque models in the carotid arteries and their reaction to the deployment of such interventional devices. Pertinent analyses will require fresh human atherosclerotic plaque material characteristics for different disease types. This study analysed atherosclerotic plaque characteristics from 18 patients tested on site, post-surgical revascularisation through endarterectomy, with 4 tissue samples being excluded from tensile testing based on large width-length ratios. According to their mechanical behaviour, atherosclerotic plaques were separated into 3 grades of stiffness. Individual and group material coefficients were then generated analytically using the Yeoh strain energy function. The ultimate tensile strength (UTS) of each sample was also recorded, showing large variation across the 14 atherosclerotic samples tested. Experimental Green strains at rupture varied from 0.299 to 0.588 and the Cauchy stress observed in the experiments was between 0.131 and 0.779 MPa. It is expected that this data may be used in future design optimisation of next generation interventional medical devices for the treatment and revascularisation of diseased arteries of the carotid bifurcation.     

Differential effects of insulin-like growth factor-1 and atheroma-associated cytokines on cell proliferation and apoptosis in plaque smooth muscle cells of symptomatic and asymptomatic patients with carotid stenosis

Morbidity and mortality from atherosclerosis are associated with complicated atherosclerotic lesions due to plaque rupture, which is regulated by a balance between proliferation and apoptosis of vascular smooth muscle cells (VSMC). We examined insulin-like growth factor-1 (IGF-1)-induced survival of plaque VSMC from carotid endarterectomy specimens and investigated the underlying cellular mechanisms in the presence and absence of IL-12 and IFN-gamma. Both IL-12 and IFN-gamma were strongly expressed in symptomatic atherosclerotic plaques as compared with asymptomatic plaques. In asymptomatic plaque VSMC, IGF-1 induced the survival and proliferation of VSMC and accelerated VSMC into S-phase. IL-12 or IFN-gamma inhibited proliferation and VSMC were arrested in the G0-G1 phase. IGF-1 markedly inhibited the expression of p27(kip) and p21(cip) and significantly induced cyclin E and cyclin D. Both cytokines by themselves increased the expression of p27(kip) and p21(cip) and inhibited cyclin E and cyclin D. On the contrary, in symptomatic VSMC there was already increased apoptosis of VSMC and there was no significant effect of IGF-1 or inflammatory cytokines on proliferation, apoptosis or the expression of p27(kip) and p21(cip) and cyclin D and E. These data suggest that IGF-1 is more potent in inducing the survival of VSMC from the endarterectomy specimens of asymptomatic patients as compared to that of symptomatic subjects and cytokines associated with atheroma lesions decrease the activity of IGF-1-induced survival in the VSMC of asymptomatic plaques. The different expression and activity of cell cycle regulatory proteins could be responsible for apoptosis of VSMC and destabilization of atherosclerotic plaques.     

颈动脉粥样硬化斑块发生的危险因素及与脑梗死的关系

目的:研究颈动脉粥样硬化斑块发生的危险因素及与脑梗死的关系。方法:选取2013年7月到2014年7月我院收治的脑梗死患者120例(研究组),另选取非脑梗死患者或者健康体检者120例(对照组),对所有入选者实施颈部血管超声检查,并检测其血糖、血浆纤维蛋白原和血脂,比较两组颈动脉粥样硬化斑块的数目、部位、颈动脉内径并分析脑梗死危险因素。结果:研究组斑块检出率和斑块数显著高于对照组,两组比较差异具有统计学意义(P0.05);颈总动脉内径显著小于对照组,两组比较差异具有统计学意义(P0.05);斑块存在于颈总动脉者最多,且与脑梗死部位存在同侧相关性(P0.05);研究组年龄、高血压、糖尿病和血脂、纤维蛋白原(FIB)也显著高于对照组,两组比较差异具有统计学意义(P0.05)。结论:颈动脉粥样硬化斑块发生和脑梗死存在密切关系,年龄、糖尿病、高血压、FIB和血脂均是其危险因素。     

Oxysterols and symptomatic versus asymptomatic human atherosclerotic plaque

Atherosclerosis is the most common cause of mortality in the Western world, contributing to about 50% of all deaths. Atherosclerosis is characterized by deposition of lipids onto the coronary or carotid arterial wall and formation of an atherosclerotic plaque. Atherosclerotic plaques are categorized into two groups: symptomatic and asymptomatic. The symptomatic plaques tend to be unstable and prone to rupture, and are associated with an increase in ischemic events. Oxysterols, products of cholesterol oxidation, are cytotoxic materials. Their level and type may be associated with plaque formation, development and stability. Oxysterols stimulate the formation of foam cells, advance atherosclerotic plaque progression, and contribute to plaque vulnerability and instability due to their cytotoxicity and their ability to induce cell apoptosis. Studies indicate that plasma 7β-OH CH level can be used as a biomarker for detecting carotid and coronary artery disease. Further clinical studies are needed to evaluate the potential of oxysterols for use as biomarkers for plaque vulnerability and instability. The identification of biomarkers in the blood that can distinguish between symptomatic and asymptomatic plaques remains an unresolved issue.     

Shear strain in the adventitial layer of the arterial wall facilitates development of vulnerable plaques

Myocardial infarction and stroke are two of the leading causes of death and primarily triggered by destabilization of atherosclerotic plaques. Fatty streaks are known to develop at sites in the arterial wall where shear stress is low. These fatty streaks can develop into more advanced plaques that are prone to rupture. Rupture leads to thrombus formation, which may subsequently result in a myocardial infarction or stroke. The relation between shear stress on the inner (endothelial) layer of the arterial wall in relation to plaque development has been studied extensively. However, a causal relation between adventitial shear forces and atherosclerosis development has never been considered.Arterial stiffening increases with age and may facilitate an increase in shear strain in the adventitial layer, an axial shear between artery and surrounding tissue. In the adventitial layer, a large number of inflammatory cells and perivascular structures are present that are subjected to shear strain. Cyclic strain applied to endothelial cells stimulates neovascularisation via different pathways. The conduit arteries in the human body (e.g. coronary and carotid artery) have their own nutrition supply: the vasa vasorum, which is located in the adventitial layer and sprouts into the intimal layer when atherosclerotic plaque develops. Increased plaque neovascularisation makes the plaques more prone to rupture. Therefore we hypothesize that increased shear strain facilitates the development of vulnerable plaques by stimulation of atherosclerotic plaque neovascularisation that sprouts from the adventitial vasa vasorum. Validation of this hypothesis paves the road to the use of adventitial shear strain (measured using a noninvasive ultrasound technique) as risk assessment in plaque.     

脑卒中患者血管危险因素与颈动脉粥样硬化的关系

目的研究脑卒中患者血管危险因素与颈动脉粥样硬化的关系。方法受试者151人主要为脑梗死及椎-基底动脉供血不足病例。将所有受试对象行颈动脉超声检查,采用二分类变量的Logistic回归分析方法对其危险因素进行筛选,找出与颈动脉粥样硬化改变相关的因素。结果年龄及吸烟与颈动脉内中膜增厚之间存在相关性,P=0.006（OR=1.08,95%CI 1.02-1.14）和0.01（OR=5.09,95%CI 1.47-17.61）;年龄、吸烟同样与颈动脉斑块之间存在相关性,P=0.006（ORn=n1.06,95%CI 1.06-1.11）和0.04（ORn=2.97,95%CI 1.04-8.50）,收缩压与颈动脉斑块呈正相关,P=0.04（OR=1.03,95%CI 1.00-1.05）,舒张压与颈动脉斑块呈负相关P=0.04（OR=0.96,95%CI 0.92-1.00）。结论随年龄的增大动脉内中膜增厚及颈动脉斑块的患病率增加,吸烟者内中膜增厚及颈动脉斑块比率高于不吸烟者;收缩压增加颈动脉斑块患病率增加,舒张压增加斑块患病率下降。     

Dichotomy in Hedgehog Signaling between Human Healthy Vessel and Atherosclerotic Plaques

The major cause for plaque instability in atherosclerotic disease is neoangiogenic revascularization, but the factors controlling this process remain only partly understood. Hedgehog (HH) is a morphogen with important functions in revascularization, but its function in human healthy vessel biology as well as in atherosclerotic plaques has not been well investigated. Hence, we determined the status of HH pathway activity both in healthy vessels and atherosclerotic plaques. A series of 10 healthy organ donor-derived human vessels, 17 coronary atherosclerotic plaques and 24 atherosclerotic carotid plaques were investigated for HH pathway activity. We show that a healthy vessel is characterized by a high level of HH pathway activity but that atherosclerotic plaques are devoid of HH signaling despite the presence of HH ligand in these pathological structures. Thus, a dichotomy between healthy vessels and atherosclerotic plaques with respect to the activation status of the HH pathway exists, and it is tempting to suggest that downregulation of HH signaling contributes to long-term plaque stability.     

Association of body iron stores with low molecular weight iron and oxidant damage of human atherosclerotic plaques

The association between iron, an oxidant catalyst, and atherosclerosis is controversial. In particular, it is unknown whether: (1) stored iron, namely serum ferritin, is correlated with catalytic iron and oxidant damage of human atherosclerotic plaques; (2) catalytic iron is related to oxidative injury within such plaques; (3) plaque oxidant burden is associated with the severity of atherosclerosis. Thus, we assessed low molecular weight iron (LMWI), which represents the metal catalytically active form, together with fluorescent damage products of lipid peroxidation (FDPL) and lipid hydroperoxides (LOOH), in 38 atherosclerotic plaques surgically removed from 38 patients who had undergone selective carotid endarterectomy. In each patient, the levels of serum ferritin were measured and correlated with those of plaque LMWI and lipoperoxides by the Spearman rank correlation test with Spearman rank correlation coefficient (r(S)) calculation. Moreover, in patients selected from the same study population, we compared plaque analyte levels between two groups with different severity of atherosclerotic carotid stenosis, i.e., <90% (group A, n = 25) or > or =90% (group B, n = 13), and between another two groups without (group C, n = 27) and with (group D, n = 11) associated contralateral carotid stenosis > or =50%, indicative of "extensive" and more severe atherosclerotic disease. In group A patients, serum ferritin was directly and significantly correlated with plaque LMWI (r(S) = 0.46, P < 0.025) and FDPL (r(S) = 0.58, P < 0.005), while its correlation with plaque LOOH, albeit direct, did not attain statistical significance. Moreover, a direct and significant relationship was evident between the plaque content of LMWI and that of both FDPL (r(S) = 0.61, P < 0.0025) and LOOH (r(S) = 0.51, P < 0.025), suggesting a prooxidant role of catalytic iron within human atherosclerotic plaques. Considering the 13 patients of group B, a positive and significant correlation was observed between the levels of serum ferritin and those of plaque LMWI (r(S) = 0.83, P < 0.0001); on the other hand, serum ferritin, as well as plaque LMWI, showed no significant correlation with either plaque FDPL or LOOH, conceivably reflecting the small number of patients belonging to group B. Finally, plaque LMWI, FDPL, and LOOH content was significantly higher in group B than in group A, and in group D than in group C. These data suggest a role for catalytic iron in atherosclerotic plaque oxidation and in the severity of atherosclerosis, which appears indeed associated with plaque oxidant burden.     

Atherosclerotic plaques occur in absence of intima-media thickening in both systemic sclerosis and systemic lupus erythematosus: a duplexsonography study of carotid and femoral arteries and follow-up for cardiovascular events

Introduction

The objective of this cross-sectional and retrospective cohort study was (1) to determine the usefulness of intima-media thickness (IMT) in contrast to plaque assessment, (2) to examine the value of additive femoral artery sonography and (3) to identify potential risk factors for atherosclerosis and incident cardiovascular events in systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) patients.

Methods

In this study, 90 SSc and 100 SLE patients were examined by duplexsonography. IMT was measured in common carotid and common femoral arteries, plaques were assessed in common, internal and external carotid and common, proximal superficial and deep femoral arteries. Different definitions of pathological IMT (pIMT) were compared with the presence of plaque. Results were evaluated in relation to traditional and non-traditional risk factors for baseline atherosclerosis (logistic regression) and their predictive value for cardiovascular events during follow-up (cox regression).

Results

Definite atherosclerosis occurred frequently without signs of subclinical atherosclerosis in both diseases: pIMT >0.9 mm was present in only 17/59 (28.9%) SSc and 13/49 (26.5%) SLE patients with already present atherosclerotic plaques. Using age-adjusted pIMT definitions, this rate was even lower (5.1-10.3% in SSc, 14.3-26.5% in SLE). Plaques were located only at the carotid or only at the femoral arteries in 26 (13.7%) and 24 (12.6%) patients, respectively. Age and nicotine pack-years were independently associated with atherosclerotic plaques in SLE and SSc patients, as well as the cumulative prednisolone dose in SSc subgroup, and ssDNA positive SLE patients had a lower risk for atherosclerotic plaque. During follow-up (available for 129/190 (67.9%) patients, 650 person-years), cardiovascular events occurred more often in patients with coronary heart disease (adjusted-hazards ratio (HR) 10.19, 95% confidence interval (CI) 3.04 to 34.17, P <0.001), male patients (adjusted-HR 8.78, 95% CI 2.73 to 28.19, P <0.001) and in patients with coexistent carotid and femoral plaques (adjusted-HR 5.92, 95% CI 1.55 to 22.67, P = 0.009). Patients with solely carotid or femoral plaque were not at higher risk.

Conclusion

Atherosclerotic plaque lesions can be found frequently in absence of intima-media thickening in both SSc and SLE patients. As well as routine sonography of carotid arteries, the sonography of femoral arteries is recommended to identify additional atherosclerotic lesions and to detect patients at a high risk for cardiovascular events.     

Expression of NPP1 is regulated during atheromatous plaque calcification

Mutations of the ENPP1 gene encoding ecto‐nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) are associated with medial calcification in infancy. While the inhibitory role of matrix proteins such as osteopontin (OPN) with respect to atherosclerotic plaque calcification has been established, the role of NPP1 in plaque calcification is not known. We assessed the degree of plaque calcification (computed tomography), NPP1 and OPN localization (immunohistochemistry) and expression (RT‐PCR) in a cohort of 45 patients undergoing carotid endatherectomy for significant stenosis of the internal carotid artery and in normal arteries (N= 50). We correlated NPP1 and OPN expression levels to the degree of plaque calcification, to pro‐atherogenic factors and statin therapy. NPP1 was demonstrated in the base and in the shoulder of atherosclerotic plaques. Compared to normal arteries and non‐calcified plaques, in calcified plaques NPP1 mRNA was decreased (P < 0.0001). OPN mRNA levels were up‐regulated in carotid atheroma. NPP1 and OPN expression levels positively correlated with the degree of plaque calcification (R= 0.54, P= 0.00019 and R= 0.46, P= 0.017, respectively) and with risk factors of atherosclerosis. Expression of the calcification inhibitor NPP1 is down‐regulated in calcified atherosclerotic plaques. Our correlation data point to a counter‐active mechanism, which in the end turns out to be insufficient to prevent further progression of calcification.     

大鼠局灶性脑缺血模型的有效制备

目的比较三种不同手术方法制作大鼠永久性脑缺血模型的效果,包括死亡率、神经功能评分、脑梗死体积、手术效率。方法将采用不同手术方法制备脑缺血模型的大鼠随机分为三组。1组在术中分别结扎颈总动脉（CCA）、颈外动脉（ECA）、枕动脉、翼腭动脉,并且用动脉夹对颈内动脉（ICA）进行临时夹闭;2组在术中分别结扎颈总动脉、颈外动脉,暴露枕动脉和翼腭动脉但不结扎,用丝线悬挂颈内动脉而不是用动脉夹夹闭,线栓在显微镜直视下插入颈内动脉越过翼腭动脉起始点至大脑中动脉分叉处;3组只暴露颈总动脉、颈外动脉和颈内动脉,结扎颈总动脉、颈外动脉,丝线悬挂颈内动脉,显微镜下将线栓盲插至颈内动脉大脑中动脉分叉处。分别检测三组模型的死亡率、神经功能评分、梗死体积、手术时间。结果第3组制作动物模型的方法所花费时间平均为17.5 min,死亡率较低,神经功能评分及梗死体积稳定。结论采用第3组手术方法可以缩短手术时间,提高手术效率,能够高效地制作出更加稳定的可用于临床实验的大鼠脑缺血模型。     

The carotid plaque imaging in acute stroke (CAPIAS) study: protocol and initial baseline data

Background

In up to 30% of patients with ischemic stroke no definite etiology can be established. A significant proportion of cryptogenic stroke cases may be due to non-stenosing atherosclerotic plaques or low grade carotid artery stenosis not fulfilling common criteria for atherothrombotic stroke. The aim of the CAPIAS study is to determine the frequency, characteristics, clinical and radiological long-term consequences of ipsilateral complicated American Heart Association lesion type VI (AHA-LT VI) carotid artery plaques in patients with cryptogenic stroke.

Methods/Design

300 patients (age >49 years) with unilateral DWI-positive lesions in the anterior circulation and non- or moderately stenosing (<70% NASCET) internal carotid artery plaques will be enrolled in the prospective multicenter study CAPIAS. Carotid plaque characteristics will be determined by high-resolution black-blood carotid MRI at baseline and 12 month follow up. Primary outcome is the prevalence of complicated AHA-LT VI plaques in cryptogenic stroke patients ipsilateral to the ischemic stroke compared to the contralateral side and to patients with defined stroke etiology. Secondary outcomes include the association of AHA-LT VI plaques with the recurrence rates of ischemic events up to 36 months, rates of new ischemic lesions on cerebral MRI (including clinically silent lesions) after 12 months and the influence of specific AHA-LT VI plaque features on the progression of atherosclerotic disease burden, on specific infarct patterns, biomarkers and aortic arch plaques.

Discussion

CAPIAS will provide important insights into the role of non-stenosing carotid artery plaques in cryptogenic stroke. The results might have implications for our understanding of stroke mechanism, offer new diagnostic options and provide the basis for the planning of targeted interventional studies.

Trial Registration

NCT01284933

     

血清MMP-8、IL-6表达与缺血性脑血管病患者颈动脉粥样硬化斑块的关系研究

目的：研究血清基质金属蛋白酶-8(MMP-8)、白细胞介素-6(IL-6)表达与缺血性脑血管病患者颈动脉粥样硬化斑块的关系。 方法：选取2012 年9 月至2013 年11 月就诊60 例缺血性脑血管病患者为研究组和健康体检者60 例为对照组。按照超声影像学 资料并参考患者颈动脉斑块类型把研究组分为不稳定斑块类型(18 例),稳定斑块类型(22 例)以及斑块性质介于两组之间为中间 类型(20 例)。采用双抗体夹心酶联免疫吸附试验(ELISA)对血清MMP-8、IL-6 水平进行测定,探讨血清MMP-8、IL-6 表达与不同 程度缺血性脑血管病患者颈动脉粥样硬化斑块的关系。结果：研究组血清MMP-8、IL-6 水平显著高于对照组,差异均有统计学意 义(P<0.01);三种不同类型斑块血清中MMP-8、IL-6 水平差异均有统计学意义(P<0.01);Spearman 等级相关性分析发现,研究组患 者颈动脉斑块稳定程度与血清MMP-8、IL-6 浓度水平存在显著正相关关系(P<0.01);线性相关分析发现,研究组血清MMP-8 水 平与IL-6 水平呈正相关关系(P<0.01)。结论：缺血性脑血管病患者血清MMP-8、IL-6 水平明显升高,其与颈动脉斑块不稳定程度 相关,同样与缺血性脑血管病发病机制方面存在相关协同作用。     

Expanding expression of the 5-lipoxygenase/leukotriene B4 pathway in atherosclerotic lesions of diabetic patients promotes plaque instability

Emerging evidence now indicates that the 5-lipoxygenase (5-LO) pathway play a role in the pathogenesis of atherosclerosis and restenosis. The expression of 5-LO by activated macrophages in symptomatic plaques leads to leukotriene B(4) (LTB(4)) accumulation and enhanced synthesis and release of matrix metalloproteinases (MMPs) that can promote plaque rupture. However, the role of 5-LO pathway in diabetic vascular disease has not been previously reported. Thus, the present study was designed to analyze the expression of 5-LO in carotid plaques of diabetic patients and to investigate the possible role of 5-LO pathway in the pathogenesis and progression of diabetic atherosclerosis. Atherosclerotic plaques from 60 patients undergoing carotid endarterectomy were divided into non-diabetic and diabetic group. Plaques were analyzed for 5-LO, MMP-2 and MMP-9 by immunohistochemical, Western blot, and densitometric analyses, whereas zymography was used to detect MMP activity. Immunocytochemistry was also used to identify CD68+macrophages, CD3+T-lymphocytes, and HLA-DR+inflammatory cells. LTB(4) were quantified by enzyme-linked immunosorbent assay. 5-LO showed abundant immunoreactivity in human atherosclerotic carotid lesions, and was colocalized with macrophage infiltrates in atherosclerotic intima. 5-LO expression was higher in diabetic compared with non-diabetic plaques and was associated with increased MMP-2 and MMP-9 expression. Follow-up analyze with zymography assay revealed MMP activity was elevated in diabetic compared with non-diabetic plaques. Notably, in contrast to non-diabetic plaques, LTB(4) levels were significantly increased in diabetic plaques by enzyme-linked immunosorbent assay. These results suggest that overexpression of 5-LO and LTB(4) in atherosclerotic plaques possibly promote MMP-induced plaque rupture in diabetes. Hence, anti-LTs may be useful, not only in reducing atherogenesis, but also in the prevention and treatment of acute atherothrombotic events in diabetic patients.